To attain high cross country speed a suspension is required that enables a vehicle to follow the general contour of the terrain but allows the vehicle to traverse discrete obstacles such as bumps, rocks, logs, etc., without any disturbing effect on the vehicle. Ideally, this requires that the movement of individual suspension units do not increase or decrease the support force on the vehicle, i.e., a constant force (zero rate) suspension system. It is also required that the system ride characteristics insofar as possible remain the same with and without payload, and possess low natural frequency for soft ride and low vehicle maintenance. These latter conditions are met with conventional air bag springs. Thirdly, the suspension system as a whole must have a variable high rate suspension characteristic to enable the vehicle to follow the general contour of the terrain while possessing high lateral and longitudinal stability. The stability is required to meet high pitch, vertical and roll accelerations encountered in panic braking, cornering and traversing cross country terrain macro obstacles.